Integrate SliceViewer from VTK in QT-Application

Hi all,
i am working on ubuntu 12.04, i use VTK 6.0.0 and QT 4.8.1.
I want to use a SliceViewer in my application, the Viewer is from this example
"Your text to link here...":http://www.vtk.org/Wiki/VTK/Examples/Cxx/IO/ReadDICOMSeries
The example works, but when i put in my application, i get only a black screen
with the correct number of slices in the chossen folder.
@cmake_minimum_required(VERSION 2.8)